The invention relates to a method for multiplexing digital data, and software for that purpose.
In practice very many methods to send data are known, particularly through a network. An example are digital data that are sent through the internet, but also digital telephone signals, such as for instance in case of cordless GSM telephones.
In practice there are also various methods known for multiplexing digital data.
The data are sent via a medium in the form of data packets, This can take place via a physical cabling in for instance copper or glass fibre, or via infrared or radio waves.
Because the capacity, often coupled to bandwidth, of the media over which the data are being sent mostly is too small, the data are often compressed. However, this has often appeared not to be sufficient.
Additionally many of these methods are aimed at optimising the data transfer between two computers.
It is among others an object of the present invention to at least partially solve these problems. To that end the invention provides a method for multiplexing digital data, wherein a packet of digital data is simultaneously sent from front to rear and from rear to front. Additionally the invention provides a method for multiplexing digital data, wherein a packet of digital data is simultaneously sent from the beginning of the packet towards the end and from the end towards the beginning. Additionally the invention provides a method for multiplexing digital data, wherein simultaneously a packet of digital data is sent and the same packet is sent backwards.
By splitting the data stream in two simultaneous streams, wherein the one stream starts sending the data from the front and works its way to the rear, and the other stream works its way from the rear to the front, the possibility is given to very quickly send data between and to for instance computers. In most of the cases, the invention relates to sending this data via electromagnetic waves, eg electronically or optically.
Another advantage of the method is that no other control signals or techniques are necessary to reconstruct the entire signal or data packet or to adjust both streams to each other: the signal or data packet is complete when the two streams meet each other, or when the data buffer is full. Delays in one of either lines do not lead to loss of signal.
In many cases the data connection is a-symmetrical: the transmission capacity is smaller than the receiving capacity. In the method according to the invention it is possible, despite the smaller transmission capacity, to nonetheless use the full receiving capacity. This may for instance be of importance in so-called streaming broadcasts through the internet, wherein through the internet digital radio broadcasts and in future even television or video can take place. Both data streams can also enter via various lines.
For instance the one data stream can for example enter via a telephone line and the second data stream via a cable, the electricity grit or cordless via GSM. It is also possible to let the data streams enter via one cable by means of physical multiplexing. The invention therefore actually offers a specific form of digital multiplexing.
Preferably the present invention relates to a method as described, wherein a first device sends the data from front to rear to a third device, and a second device sends the same data from rear to front to the third device. As a result the third device is able to have all data available very quickly.
Preferably the third device places the data in a data buffer the size of the packet, and sends a signal to the first and second device when either the buffer is full, or stops sending confirmations until the buffer is full. In this way the coordination between both streams is very simple.
It is preferred that in a method according to the invention a first device sends data from front to rear to a second device, and simultaneously backwards to a third device. As a result the possibility is offered to very quickly provide two devices with all data, with an optimally used bandwidth. In this method it is preferred that the second device and third device immediately at receipt forward the data they received from the first device to each other. As a result both devices can optimally use their bandwidth and transmission capacity.
In said method it is preferred that the second and third device have been provided with a data buffer the size of the packet, wherein the received data are placed in the data buffer and the first and second device send a signal to the first device when the respective data buffer is full.
Additionally the invention relates to a method for sending a data packet to a first device in an organic (also called xe2x80x98ad-hocxe2x80x99) data network of devices, wherein the devices have been provided with a data processing unit, a data buffer and software having receiving routines for receiving data packets from at least two transmitting devices in the data network, wherein at least two other devices in the network simultaneously send complementary data packets to the first device which added together form the data packet.
Preferably said software has further been provided with transmission routines for transmitting data packets, received from the transmitting device or devices in the data network to at least one receiving device that is connected to the data network, independent of the transmitting device or devices.
Additionally the invention relates to a method for receiving digital data, wherein a device provided with data storage means creates a data buffer in the data storage means the size of a packet of digital data, and simultaneously receives a first stream of digital data and receives a second stream of digital data, wherein the device fills the data buffer from front to rear with the first stream of digital data and fills the data buffer from rear to front with the second stream of digital data.
Preferably the device informs the source or sources of the streams of digital data when a data buffer is full. As a result the coordination is simple.
Additionally the invention relates to a method for sending digital data, wherein a device provided with data storage means creates a data buffer in the data storage means, stores digital data in the data buffer, and from the front of the data buffer and the rear of the data buffer sends the digital data in two streams.
Preferably the device stops sending after receipt of a signal. As a result the coordination is again simple.
Additionally the invention relates to software provided with routines for carrying out the method according to one of methods mentioned above.
From the above description, in combination with the figures and their description, it will immediately be clear to an expert which routines are necessary to that end, and how said routines have to function with respect to each other. Such software may of course be immediately implemented in hardware, for instance in a PROM, EPROM or the like.
Additionally, the invention relates to an software for sending a packet of digital data, comprising a first transmission routine for sending a first stream of digital data starting from the front of the packet of digital data and a second transmission routine for sending a second stream of digital data starting from the end of the packet of digital data.
Furthermore, the invention relates to software for receiving a packet of digital data, comprising a first receiving routine for receiving a first stream of digital data and a second recieving routine for simultaneously receiving a second stream of digital data, and a first storing routine for storing the first stream of digital data in a memory starting at the front of the memory and filling the memory towards the end, and a second storing routine for storing the second stream of digital data starting at the end of the memory and filling the memory towards the front, and a stop routine for ending the receiving of digital data when the memory is full.
Furthermore, the invention relates to an apparatus for sending a packet of digital data, comprising memory means for storing the packet of digital data, first sending means for sending a first stream of digital data, starting at the front of the memory means and second sending means for sending a second stream of digital data, starting at the end of the memory means.
Furthermore, the invention relates to an apparatus for receiving a packet of digital data, comprising memory means for storing the packet of digital data, first receiving means for receiving a first stream of digital data, and storing it in said memory means, starting from the front of the memory means, and second receiving means for receiving a second stream of digital data, and storing it in said memory means, starting from the back of the memory means.
Additionally the invention relates to a carrier provided with software as described, and to a device provided with software as described.
In a specific embodiment of the invention, packets of digital data are sent in the form of bitstreams. In another embodiment, the packets are divided into smaller sub-packets, for instance numbered 1 . . . n. In this case, the sub-packets are sent 1, 2, etc in the first stream, i.e. sequentially, starting with the first sub-packet, and the sub-packets are sent n, nxe2x88x921, . . . etc in the second stream, i.e. sequentially, starting with the last sub-packet. In a further embodiment, these two streams are sent almost simultaneous. The two streams can be sent over the same carrier, for instance using conventional multiplexing techniques, or they can be sent over entirely different carriers, for instance cable modem and telephone line. The digital data can also be of another form instead of the now-used binairy data.